core: support oauth bind/unbind account (#971)

Co-authored-by: panda <panda_dtdyy@outlook.com>

packages/telegram/templates/telegram_login.html

@@ -0,0 +1,20 @@
+{% extends "layout/immersive.html" %}
+{% block content %}
+<div class="row"><div class="columns">
+    <div class="immersive--content immersive--center">
+        <div class="row"><div class="columns">
+            <h1>{{ _('Login with Telegram') }}</h1>
+        </div></div>
+    </div>
+</div></div>
+<div class="row"><div class="columns" id="telegram-login" style="text-align: center;">
+    <script async src="https://telegram.org/js/telegram-widget.js?22"
+        data-telegram-login="{{ botLogin }}" data-size="large" data-onauth="onTelegramAuth(user)"
+        data-request-access="write"></script>
+    <script type="text/javascript">
+        function onTelegramAuth(user) {
+            window.location.href = '/oauth/telegram/callback?payload=' + encodeURIComponent(JSON.stringify(user));
+        }
+    </script>
+</div></div>
+{% endblock %}